Studies on the tumor-promoting activity of polyethylene: inhibitory activity of metabolic cooperation of polyethylene films containing an antioxidant

Tumor-promoting activity, inhibitory activity on the gap-junctional intercellular communication of polyethylene (PE) film containing a model antioxidant, 2,2'-methylene-bis(4-methyl-6-tert-butylphenol) (MBMBP), at various amounts was assessed by V79 metabolic cooperation (MC) assay. The extracts prepared from PE film containing MBMBP showed the inhibitory activities and the potencies of the inhibitory activities depended on the amount of MBMBP involved in the film, whereas the extract prepared from MBMBP-free PE film did not show any inhibitory activities. However, the inhibitory activities were observed when MC assay was carried out on the surface of the MBMBP-free film. These findings indicate that tumor-promoting activity of PE film is influenced by the surface property of the film as well as by amount and kind of additives incorporated.